How to reuse CyclicBarrier in Java?

How to reuse CyclicBarrier in Java?

I'll respond in English as per your request!

In Java, the CyclicBarrier class is used to coordinate a fixed number of threads until all of them have reached the barrier. Once all threads have crossed the barrier, they can continue executing.

To reuse a CyclicBarrier, you need to reset it after it has been broken. Here's an example:

import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class ReuseCyclicBarrier {
public static void main(String[] args) throws InterruptedException {
final int numThreads = 3; // number of threads
final CyclicBarrier barrier = new CyclicBarrier(numThreads);
ExecutorService executor = Executors.newFixedThreadPool(numThreads);
for (int i = 0; i < numThreads; i++) {
int threadNumber = i;
Thread workerThread = new MyWorkerThread(barrier, threadNumber);
executor.submit(workerThread);
}
}
static class MyWorkerThread implements Runnable {
private final CyclicBarrier barrier;
private final int threadNumber;
public MyWorkerThread(CyclicBarrier barrier, int threadNumber) {
this.barrier = barrier;
this.threadNumber = threadNumber;
}
@Override
public void run() {
try {
// Some work
for (int i = 0; i < 3; i++) {
System.out.println("Worker " + threadNumber + ": Working...");
Thread.sleep(100); // Simulate some work
}
barrier.await(); // Wait until all threads have reached the barrier
System.out.println("Worker " + threadNumber + ": Barrier broken!");
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
try {
// Some more work after barrier is broken
for (int i = 0; i < 2; i++) {
System.out.println("Worker " + threadNumber + ": Continuing...");
Thread.sleep(100); // Simulate some more work
}
barrier.reset(); // Reset the barrier to reuse it again
} catch (BrokenBarrierException e) {
Thread.currentThread().interrupt();
}
}
}
}

In this example, three threads are created and executed concurrently. Each thread performs some work, then reaches a CyclicBarrier and waits until all threads have reached the barrier. After the barrier is broken, each thread continues with more work, resetting the barrier for reuse.

Note that you need to call reset() on the CyclicBarrier to reuse it after it has been broken.

Keep in mind that this example is simplified for illustration purposes. In real-world scenarios, you might want to add additional error handling and synchronization mechanisms to ensure correct behavior.

Java cyclicbarrier example

I'll provide an explanation of the CyclicBarrier concept and demonstrate it with a Java code example. This barrier is designed to allow multiple threads to wait until all threads have reached a certain point, like starting a shared operation.

Java Code Example:

Here's a basic demonstration of how CyclicBarrier works in Java:

import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
public class Main {
public static void main(String[] args) throws InterruptedException {
// Create the barrier with 3 parties (threads)
final int numParties = 3;
CyclicBarrier barrier = new CyclicBarrier(numParties);
for (int i = 0; i < numParties; i++) {
// Each thread waits until all threads have reached the barrier
Thread t = new Thread(() -> {
try {
System.out.println("Thread " + i + " waiting at barrier");
barrier.await();
System.out.println("Thread " + i + " has passed the barrier");
} catch (InterruptedException e) {
throw new RuntimeException(e);
} catch (BrokenBarrierException e) {
throw new RuntimeException(e);
}
});
t.start();
}
}
}

Explanation:

Let's break down how this code works:

How CyclicBarrier Works:

Advantages of CyclicBarrier:

In summary, Java's CyclicBarrier is an excellent tool for coordinating the flow of your application by allowing multiple threads to synchronize at a specified point.